Connectors for use in electrical equipment usually comprise several components which contribute to the electrical characteristics of the connector such as the connector's "insertion loss" and its filtering properties. Connectors also usually comprise an input/output network that is adapted to receive and buss the signals through the connector to an electrical device in the connector's output environment, and a printed circuit board which contains circuit elements that are adapted to ensure that the connector performs its required functions. The circuit elements also contribute to the electrical characteristics of the connector and may have both a parasitic inductance and a parasitic capacitance which adversely affect the electrical performance of the connector.
For instance, a parallel plate surface mounted capacitor will generally produce a parasitic inductance which contributes to lowering the resonant frequency of the connector. This parasitic inductance, if not correctly placed in series with a ground plane, will severely limit the frequency response of the connector and force the resonant frequency to be capped at a rather low value. Additionally, the particular printed circuit board which is used to surface mount such parallel plate capacitors in a connector also produces a parasitic inductance which, if not properly grounded, will adversely affect the frequency response of the connector by lowering the resonant frequency.
The printed circuit boards in a connector also contain circuit "traces" which electrically interface the circuit elements to the connector's input/output network. As known by those with skill in the art, a circuit trace is a conductive sheet of material, usually a copper-based alloy, that is fabricated on the circuit board and which provides a low impedance path for current to flow from the input/output network and through the circuit elements on the printed circuit board.
As with the other circuit components in the connector, the traces themselves produce a parasitic inductance which must be efficiently controlled in order to maximize the efficiency of the connector. Since the traces are typically electrically interfaced directly with the circuit elements on the circuit board, they are considered "in line" between the input/output network and the circuit elements, and they are in the direct electrical path of the signal which is bussed through the connector. Such an in-line arrangement produces an "insertion loss" which is partially a result of the parasitic inductance of the traces.
This insertion loss (measured in dB) prevents the connector from providing proper signal filtering characteristics in connector applications which require a particular frequency response. Accordingly, the properties of the particular circuit traces found on the printed circuit boards of the connector play a critical role in controlling the filtering characteristics of the connector.
Prior connectors have not been developed with the goal of minimizing the insertion loss and providing filtering characteristics which are useful for sensitive applications. Thus, prior connectors tend to be useful only in applications which are insensitive to the frequency content of the signal being bussed therethrough, and which can tolerate an insertion loss which would be otherwise unacceptable for highly sensitive data communications through a connector.
Connectors which utilize discrete circuit elements also run a high risk of surface tracking across the discrete components in high voltage applications. This is especially true with connectors that utilize surface mounted chip capacitors that have a tendency to build up a high voltage, thereby causing the chip capacitors to discharge. Surface tracking and high voltage arcing which these connectors experience are undesirable, and tend to degrade the quality of the signal being bussed through the connectors. When connectors having chip capacitors or other surface mounted circuit elements which tend to build up high voltages must be used in high voltage applications, the undesirable effects of surface tracking and arcing should be minimized. However, there has not heretofore been an adequate solution in the art to provide connectors with the ability to minimize arcing and surface tracking across discrete surface mount components.
Accordingly, there is a need in the art for high quality, electrical connectors which minimize the insertion loss, and which ensure high integrity bussing of input signals through the connector to the output environment. These connectors should also minimize surface tracking and arcing which will occur in high voltage applications. Such needs have not heretofore been fulfilled in the art.